<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <!-- 响应式网页 -->
    <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1">

    <title>{% if page.title %}{{ page.title | escape }}{% else %}{{ site.title | escape }}{% endif %}</title>
    <meta name="description"
          content="{% if page.excerpt %}{{ page.excerpt | strip_html | strip_newlines | truncate: 160 }}{% else %}{{ site.description }}{% endif %}">
    <meta name="author" content="changning">

    <meta name="twitter:card" content="summary">
    <meta name="twitter:title"
          content="{% if page.title %}{{ page.title | escape }}{% else %}{{ site.title | escape }}{% endif %}">
    <meta name="twitter:description"
          content="{% if page.excerpt %}{{ page.excerpt | strip_html | strip_newlines | truncate: 160 }}{% else %}{{ site.description }}{% endif %}">

    <meta property="og:type" content="article">
    <meta property="og:title"
          content="{% if page.title %}{{ page.title | escape }}{% else %}{{ site.title | escape }}{% endif %}">
    <meta property="og:description"
          content="{% if page.excerpt %}{{ page.excerpt | strip_html | strip_newlines | truncate: 160 }}{% else %}{{ site.description }}{% endif %}">

    <link rel="icon" type="image/png" href="/images/favicon.png"/>
    <link href="/images/favicon.png" rel="shortcut icon" type="image/png">

    <!-- pygments代码高亮，需要在main.css前面，这样才可以使后面的代码样式生效 -->
    <link rel="stylesheet" href="/css/pygments.css">
    <link rel="stylesheet" href='{{ "/css/main.css" | prepend: site.baseurl }}'>
    <link href="//netdna.bootstrapcdn.com/font-awesome/4.5.0/css/font-awesome.min.css" rel="stylesheet">

    <link rel="canonical" href="{{ page.url | replace:'index.html','' | prepend: site.baseurl | prepend: site.url }}">
    <link rel="alternate" type="application/rss+xml" title="{{ site.title }}"
          href='{{ "/feed.xml" | prepend: site.baseurl | prepend: site.url }}'>

    <!-- 谷歌站点验证 -->
    <meta name="google-site-verification" content="eN3A4zxv_JzZ-Pr_TJSOpNeu_H_hmhiDTDbAfzV9Rsw"/>
    <!-- 百度站点验证 -->
    <meta name="baidu-site-verification" content="PxzE1sRQjl"/>

    <!-- 站点统计 -->
    <script
            async src="//dn-lbstatics.qbox.me/busuanzi/2.3/busuanzi.pure.mini.js">
    </script>

    <!-- google 统计 -->
    {% if site.ga.id %}
    <script>
        (function (i, s, o, g, r, a, m) {
            i['GoogleAnalyticsObject'] = r;
            i[r] = i[r] || function () {
                (i[r].q = i[r].q || []).push(arguments)
            }, i[r].l = 1 * new Date();
            a = s.createElement(o),
                m = s.getElementsByTagName(o)[0];
            a.async = 1;
            a.src = g;
            m.parentNode.insertBefore(a, m)
        })(window, document, 'script', '//www.google-analytics.com/analytics.js', 'ga');
        ga('create', '{{site.ga.id}}', '{{site.ga.host}}');
        ga('send', 'pageview');
    </script>
    {% endif %}

</head>
